Common elements of an ID pattern

An Interaction design pattern usually consists of the following elements:

Problem: Problems are related to the usage of the system and are relevant to the user or any other stakeholder that is interested in usability.

Context: a situation (in terms of the tasks, the users and the context of use) giving rise to a usability problem. This section extends the plain problem-solutions dichotomy by describing situations in which the problems occur.

Principle: a pattern is usually based on one or more ergonomic principles such as user guidance, or consistency, or error management.

Solution: a proven solution to the problem. A solution describes only the core of the problem, and the designer has the freedom to implement it in many ways. Other patterns may be needed to solve sub problems.

Why: How and why the pattern actually works, including an analysis of how it may affect certain attributes of usability. The rationale (why) should provide a reasonable argument for the specified impact on usability when the pattern is applied. The why should describe which usability aspects should have been improved or which other aspects might suffer.

Examples: Each example shows how the pattern has been successfully applied in a real life system. This is often accompanied by a screenshot and a short description.